What is acceptance test-driven development (ATDD)?

Question

Accepted Answer

**ATDD** — practice where tests are written before development.

**Process:**
1. Discuss requirements.
2. Write acceptance tests.
3. Develop to pass tests.
4. Refactor.

**Example (Given-When-Then):**
```
Given: User is on login page
When: User enters valid credentials
Then: User is redirected to dashboard

Given: User is on login page
When: User enters invalid credentials
Then: Error message is displayed
```

**Benefits:**
- Shared understanding.
- Living documentation.
- Faster feedback.
- Better quality.

**BA role:**
- Write acceptance criteria.
- Participate in Three Amigos sessions.
- Validate tests match requirements.

Business Analyst: What is acceptance test-driven development (ATDD)?